Circulating device

ABSTRACT

This disclosure relates to a device for preventing adhesive in an adhesive coating mechanism from thickening and decreases the problem of air drying of such adhesive. A mechanism is provided to constantly recirculate liquid adhesive which is deposited between a pair of cooperating rolls so that excess liquid is removed from between the rolls and air drying thereof is substantially decreased.

United States Patent Schaeier 51 Feb. 8, 1972 [54] CIRCULATING DEVICE[72] Inventor: Charles F. Schaefer, captaints Drive film's Point, brook,Conn. 06498 221 Filed: Jan. 9, 1970 21 Appl.No.: 1,797

[52] US. Cl. ..ll8/259- [51] Int. Cl. B05c 1/08 [58]- FieldofSearch ..118/203, 227, 259, 261;

117/ l l l [56] References Cited UNITED STATES PATENTS 2,953,476 9/1960Armstrong .Q ..u7/111 2,981,226 Murray ..1 18/227 3,094,924 6/ 1963Stark .118/259 X 3,097,968 7/1963 Schaefer ..1 18/259 3,162,545 12/1964Dearsley ..1 18/203 Primary Examiner-Louis K. Rimrodt Attomey-Delio andMontgomery [57] ABSTRACT This disclosure relates to a device forpreventing adhesive in an adhesive coating mechanism from thickening anddecreases the problem of air drying of such adhesive. A mechanism isprovided to constantly recirculate liquid adhesive which is depositedbetween a pair of cooperating rolls so that excess liquid is removedfrom between the rolls and air drying thereof is substantiallydecreased.

10 Claims, 6 Drawing Figures BY Dee/ GJWQ W I32 Chades F. SchaeFerATTORNEYS HEU FEB 8 I972 sum 3 BF 2 INVENTOR CIRCULATING DEVICE Thisinvention relates to machines for applying liquid coatings such asadhesives to sheet material, and more particularly relates to suchmachines wherein the liquid is deposited between two cooperating rollswhich define a liquid reservoir therebetween.

A device of the type to which the present invention is applicable isgenerally shown in US. Pat. No. 3,097,968. In such a coating applyingapparatus there is provided a pair of cooperating rolls wherein one rollis utilized to place an adhesive coating or layer on strip materialpassing thereby. The second roll which is generally of smaller diameteris in rolling contact with the coating roll and maybe termed a coatingcontrol roll. The two rolls define a reservoir or cavity therebetweenwhich, together with suitable damming means placed at each end, retainsa liquid adhesive in the reservoir.

In operation, liquid adhesive is deposited in the reservoir through aconduit and as the two rolls rotate the coating control roll causes athin coating of the liquid adhesive to be spread evenly along thecoating roll which then contacts the sheet material passing thereby.

Where the adhesive is of the solvent-containing cement type a problem ispresented due to air drying of adhesive on the rollers, and theagitation in the adhesive produced by the rotation of the rollershastens evaporation of the solvent.

Thus, the adhesive will quickly thicken beyond the point of practicaluse. Dependent upon the type of adhesive, this thickening may take placein as little as minutes. Where the adhesive is thin with a highpercentage of solvent, the adhesive will flow to the sides of the rollsand then down to a catch tank at a substantially controlled rate.However, the solvent type adhesives generally must be used in a mixturewith a high percentage of solids and a low percentage of solvents, andthe adhesives will not flow freely towards the end of the rolls or passthrough a drain hole at a practical rate. The wider the sheet materialto be processed the greater the problem. For example, the roll lengthsmay vary from l5 up to 42 inches or greater.

The present invention is designed to overcome the problems presented bythe use of viscous liquids.

Accordingly, an object of this invention is to provide a new andimproved machine for applying a liquid coating to sheet or stripmaterial.

Another object of this invention is to provide a new and improvedadhesive applying machine. including apparatus for recirculating theadhesive to prevent rapid air drying thereof.

A further object of this invention is to provide a new and improveddevice to be used in combination with a pair of rolls defining a liquidreservoir which includes a liquid moving means which moves along thelength of the reservoir to remove excess liquid therefrom and decreasethe amount of adhesive exposed to the air.

Briefly stated, the invention in one form thereof comprises an adhesivecoating roll and a coating control roll disposed in rotating contactingrelation and defining a reservoir which holds the adhesive to be coated.The apparatus further comprises an adhesive tank together with a lead-inconduit and also a return conduit to the tank. A paddlelike member isprovided which will sweep down the length of the roll defined reservoirto remove excess liquid therefrom and propel it into the return conduit.On the return path,mechanism is provided for rotating the paddle 90 sothat it will not produce flow of the liquid in the opposite direction.

The features of the invention which are believed to be novel areparticularly set forth and distinctly claimed in the concluding' portionof the specification. The invention, however, both as to itsorganization and operation, together with further objects and advantagesthereof, may best be appreciated by reference to the following detaileddescription taken in conjunction with the drawings, wherein:

FIG. 1 is a top plan view of the preferred embodiment of the invention,as combined with a plurality of rollers for applying glue;

FIG. 2-is a front elevational view of the preferred embodiment of theinvention shown in FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along line 44 of FIG. 3, showing thetoggle lever means in a locked position;

FIG. 5 is a view similar to FIG. 4, showing the toggle lever means inareleased position about to be engaged by an abutment member; and

FIG. 6is a view taken along line 66 of FIG. 3.

As will be described in detail hereinafter, a liquid reservoir isdefinedbetween a coating roll 14 and a coating control roll 16 togetherwith damming plates 60 and 64 at the ends of the roll. Liqiiid issupplied to the reservoir through a conduit 149 from a tank 80, and areturn to the tank from an overflow conduit 78 leading from plate 60. Tomove excess liquid to the overflow conduit, a support or carrier member84 carries a paddlelike member 138 along the length of the reservoir ina liquid sweeping position toward the overflow conduit. On the returnpath the paddlelike member is rotated 90. When the paddlelike memberreturns to its starting point it is rotated back to itls' sweepingposition and the cycle is then repeated.

With reference to FIGS. l-3, the apparatus comprises a frame lfl' havingspaced apart upright side frame members 12 and l3. A coating roll 14 anda coating control roll 16 are rotatably mounted between side frames 12and 13 on shafts 18 and 20, Irespectively. A drive means (not shown)drives a sprocket chain 22 received on a sprocket wheel 24 on a shaft 26rotatably carried by side frame 13. Shaft 26 has a gear 28 thereon indriving relation with a gear 30 on the shaft of a roll 32. A roll'34 isdriven by similar means (not shown). Rolls 32 and 34 cooperate withcoating roll 14 to apply a liquid coating to strip material passingtherebetween.

Shaft 26 carries a second sprocket member 38 which is connected to asprocket member 40 by means of a sprocket chain 42. Sprocket 40 is onthe shaft 18 of coating roll 14.

Also carried on shaft 18 is a pulley 44 which drives a belt 46 aboutapulley 48 mounted on a rod 50 which is rotatably carried by side frames12 and 13. Rod 50 is threaded and serves asa lead"v screw, as willhereinafter be explained. Gear 52 is mounted on shaft 18 so as to engageand drive a gear 54 on shaft 20 of roll 16. As sprocket chain 22 isdriven it drives shaft 26 and, in turn, roll 14. Roll 16 in contact withroll 14 is driven thereby and acts to control the layer of adhesive thatpasses between the nip of the rolls. Sheet material 56 to be coatedpasses beneath roll 14 and over rolls 32 and 34. In this manner, theliquid deposited in the reservoir between rolls 14 and 16 is carrieddown to the upper surface of material 56 and evenly applied thereto byroll 14.

Rolls 14 and 16 define a liquid cavity or reservoir 58 therebetweenwhich receives the coating liquid. The liquid in cavity 58 is maintainedtherein by a plate 60 having thereon a wear layer 62 of hard fibrousmaterial, and a plate 64 also having thereon a wear layer of hardfibrous material. Layers 62 and 66 contact the ends of rolls 14 and 16.

Plate 64 is resiliently mounted on bolts 68 carrying springs 70 toinsure a tight seal between the rolls and damming plates. A spring :72is located on a guide 74 to maintain layer 66 in contact with the endsof rolls l4 and 16. The pressure of the damming; means provided byplates 60 and 64 is not sufficient to hinderrotation of the rolls I4 and16. Plate 60 and layer 62 thereon define an aperture 75 therethroughwhich lead to a conduit 78. Conduit 78 leads to a liquid tank orreservoir 80. This permits excess liquid in cavity 58 to pass intoconduit 78 and return by gravity to tank or reservoir 80.

Carried between side frames 12 and 13 are a pair of rods 82 whichslidably carry a support or carrier member 84. A member 86 is pivotallymounted to support member 84 as more clearly shown in FIG. 3. Member 86carries a cantilever spring member 88 which is attached to a threadedshoe 90 which rides on shaft 50 as more clearly seen in FIGS. 4 and 5.When shoe 90 is in engagement with shaft 50, rotation of shaft 50 willproduce motion of carrier member 84 from side frame 12 towards sideframe 13. Cantilever spring 88 is biased upwardly by means of a spring92 connected to member 84. A toggle linkage 94 acts to either lock shoe90 on shaft 50 or upon release of the toggle permits spring 92 to liftspring 88 and shoe 90 therewith out of engagement with shaft 50. Toggle94 includes a lower lever 96 pivotally mounted to member 86 by means ofa pin 98. Lever 96 is pivotally connected at its upper end to a lever100 by means of a pin 102 and lever 100, in turn, is pivotally mountedto a block 104 carried on member 84 as by means of bolts 108 and studs110. Stud 110 is also adjustable to limit the pivotal movement of lever100.

A lever 114 is pivotally mounted to an overhanging support member 112carried on member 84. Lever 114 is adapted to reset or relock toggle 94,as will be hereinafter described.

A boltlike securing member 116 is located on arm member 84 and extendingtherefrom is a spring strip 118 which winds about a spool 120 carried onthe left upright 12, FIG. 1. Toggle 94 as shown in FIG. 4 is adapted tobe broken by an abutment member 122 carried on the right upright 12,FIGS. 1 and 2, when arm member 84 travels to the extreme right positionshown in dotted line in FIGS. 1 and 2.

When am 84 travels to the extreme-left position shown in FIGS. 1 and 2,lever 114 carried on extension 112, engages an abutment in the form of abolt 124 which is resiliently mounted to a supporting member in the formof another bolt 126 by means of a spring 128. This will again lock thetoggle 94. When toggle 94 is an unlocked or raised position, as shown inFIG. 5, nut 90 is out of engagement with shaft 50. Conversely, whentoggle 94 is in a locked position, as shown in FIG. 4, nut 90 is held inthreadable engagement with shaft 50.

When nut 90 is out of engagement with shaft 50, the tension in springstrip 118 will return carrier member 84 on slides 82 from the right-handposition to the left-hand position as shown in FIGS. I and 2.

With the mechanism thus described, it will be seen that carrier member84 initially travels from left to right, as viewed in FIG. 1, untilabutment member 122 breaks the lock of toggle 94. Then spring 118returns support arm 84 along rod 82 to the left-hand position, as shownin FIG. 1, while nut 90 is withdrawn from engagement with shaft 50.

As will now be described, the support arm carries a paddlelike memberwhich acts to return excess liquid back through conduit 78 throughreservoir 80, and is then rotated 90 as it returns through the rollcavity or reservoir to its initial position to commence another cycle ofoperation.

A shaft 132 is rotatably mounted in arm member 84 and supported thereinas by means of a washer 134. A member 136 is carried on shaft 132 whichis adapted to produce rotation thereof as hereinafter described. At thebottom of shaft 132 is a paddle member 138.

As more clearly shown in FIG. 6, shaft 132 has a portion 140 ofgenerally rectangular cross section but with two concave portionsessentially 90 apart which are adapted to be engaged by a roller 144carried on a lever 142. Lever 142 is pivotally mounted to arm member 84on the lower surface thereof.

Lever 142 is biased towards arm member 84 by means of spring 145. Shaft132 is adapted to be in either of one of two positions which are 90apart and the arrangement of lever 142, roller 144 and spring 145 inconjunction with the con- I cavities 140 acts as a detent to releasablylock shaft 132 in either one of these two positions.

When arm member 84 moves to the right as viewed in FIGS. 1 and 2, suchthat member 136 is struck by abutment 146, shaft 132 will be rotated bythe torque exerted thereon to member 136. This force will be sufficientto cause portion 140 to turn against the bias of spring 145, FIG. 6, andthen roller 144 will fall into the other concavity in portion 140. Whenthe support arm travels sufficiently to the left in the oppositedirection, arm 136 which will be 90 disposed from the position shown inFIG. 1, will hit an abutment member 148 which will then rotate shaft132, 90 in the opposite direction.

In operation, pump 152 will force the glue or other viscous liquidthrough a conduit 149 to the cavity or reservoir defined by rolls 14 and16 and dams 60 and 64. As the machine is operated, shaft 50 is driventhrough belt 46 with nut in contact therewith. Accordingly, carriermember 84 will travel from the left to the right as viewed in FIGS. 1and 2 with paddlelike member 138 moving broadside to the glue in thereservoir. As paddlelike member 138 moves along the reservoir it willpush the liquid therein into conduit 78 and, hence. return it to tank80. When arm 74 has reached the right extremity of travel, member 122breaks toggle 94 and shoe 90 is raised. At the same time, shaft 132 isrotated 90 by abutment 146 acting on member 136. Carrier member 84 isnow returned to the left under the pull of spring strip 118. At thistime, the thin edge of paddlelike member 138 travels through the liquidand thus does not move or paddle the liquid in the wrong direction. Whencarrier member 84 has traveled to the left most extremity, toggle 94will be again locked by engagement of abutment bolt 124 on lever 114 andnut 90 will be forced down into engagement on shaft 50. The describedcycle of operation will then be repeated.

A further benefit from this arrangement is the substantial eliminationof the normal rotary motion of the adhesive in the reservoir due torotation of the roll. This rotary motion agitates the liquid therein andwill unduly hasten solvent evaporation and thickening of the cement.

It may thus be seen that the objects of the invention set forth as wellas those made apparent from the preceding description are efficientlyattained. Inasmuch as other embodiments of the invention may occur toothers skilled in the art, the appended claims are intended to cover allmodifications of the disclosed embodiments of the invention as well asother embodiments thereof.

What is claimed is:

1. A device for use in combination with an apparatus for applying aviscous liquid through a narrow elongated orifice and having anelongated reservoir defined above said orifice, a liquid tank, a conduitleading from said tank to the reservoir, an overflow opening at one endof said reservoir defining means, a second conduit providingcommunication between the overflow opening and the tank together withmeans for moving liquid from the tank to the reservoir, comprising acarrier member, means movably mounting said carrier member above saidreservoir, a generally flat surfaced paddlelike member carried by saidcarrier member extending into the reservoir, means for moving saidcarrier member on said mounting means toward the overflow aperture sothat said paddlelike member forces liquid in the reservoir toward theoverflow aperture, means for rotating said paddlelike member as it nearssaid overflow aperture and returning said paddlelike member toward theother end of the reservoir whereby a minimum surface area of saidpaddlelike member is presented to the liquid upon the return travel.

2. The device of claim 1 further including spaced apart frame means andsupport means comprising rods upon which said carrier member is slidablecarried between said frame means.

3. The device of claim 2 wherein said drive means includes a threadedshaft rotatably mounted between said frame means, and a threaded memberon said carrier adapted to be engaged on said shaft.

4. The device of claim 3 further including a locking mechanism forholding said shoe on said shaft, means for unlocking said lockingmechanism and lifting said shoe when said paddlelike member approachessaid overflow aperture.

5. The device of claim 4 wherein said locking mechanism is a two-linktoggle and said means for unlocking is an abutment member which isstruck by said toggle linkage as the paddlelike member approaches theoverflow aperture end of the reservoir.

6. The device of claim 4 further including means disposed at thenonoverflow aperture end of the reservoir for relocking tionsessentially 90 apart, means mounted to both of said frame means forrotating said paddlelike member between said two positions.

8. The device of claim 4 wherein said locking means is a two-linktoggle, one end of one toggle link being pivotally mounted to saidcarrier member, one end of said other toggle link being pivotallymounted to said shoe, the other ends of said links being pivotallymounted to each other.

9. The device of claim 4 further including spring means for returningsaid carrier member toward the other end of said reservoir.

10. Apparatus for applying liquid adhesive or the like to sheet or slabmaterial, spaced apart support means, a coating roll and coating controlroll rotatably supported between said support means in rolling contactand defining a reservoir therebetween, end plates at the opposite end ofthe rolls extending above the line of rolling contact of the rolls andarranged to define the reservoir with the rolls, one of the end plateshaving an overflow opening therein, a tank, a conduit extending from theoverflow opening to the tank, a pump and conduit for delivering liquidfrom the tank to the reservoir; a member movable back and forth oversaid reservoir and a generally flat surfaced paddlelike member connectedto said member movable so that said paddlelike member forces liquid inthe reservoir toward the overflow opening and means for rotating saidpaddlelike member as it nears said overflow opening and returning saidpaddlelike member toward the other end of the reservoir whereby aminimum surface area of said paddlelike member is presented to theliquid upon the return travel.

1. A device for use in combination with an apparatus for applying aviscous liquid through a narrow elongated orifice and having anelongated reservoir defined above said orifice, a liquid tank, a conduitleading from said tank to the reservoir, an overflow opening at one endof said reservoir defining means, a second conduit providingcommunication between the overflow opening and the tank together withmeans for moving liquid from the tanK to the reservoir, comprising acarrier member, means movably mounting said carrier member above saidreservoir, a generally flat surfaced paddlelike member carried by saidcarrier member extending into the reservoir, means for moving saidcarrier member on said mounting means toward the overflow aperture sothat said paddlelike member forces liquid in the reservoir toward theoverflow aperture, means for rotating said paddlelike member as it nearssaid overflow aperture and returning said paddlelike member toward theother end of the reservoir whereby a minimum surface area of saidpaddlelike member is presented to the liquid upon the return travel. 2.The device of claim 1 further including spaced apart frame means andsupport means comprising rods upon which said carrier member is slidablecarried between said frame means.
 3. The device of claim 2 wherein saiddrive means includes a threaded shaft rotatably mounted between saidframe means, and a threaded member on said carrier adapted to be engagedon said shaft.
 4. The device of claim 3 further including a lockingmechanism for holding said shoe on said shaft, means for unlocking saidlocking mechanism and lifting said shoe when said paddlelike memberapproaches said overflow aperture.
 5. The device of claim 4 wherein saidlocking mechanism is a two-link toggle and said means for unlocking isan abutment member which is struck by said toggle linkage as thepaddlelike member approaches the overflow aperture end of the reservoir.6. The device of claim 4 further including means disposed at thenonoverflow aperture end of the reservoir for relocking said lockingmechanism.
 7. The device of claim 2 wherein said paddlelike member ismounted to said carrier member for rotation between positionsessentially 90* apart, means mounted to both of said frame means forrotating said paddlelike member between said two positions.
 8. Thedevice of claim 4 wherein said locking means is a two-link toggle, oneend of one toggle link being pivotally mounted to said carrier member,one end of said other toggle link being pivotally mounted to said shoe,the other ends of said links being pivotally mounted to each other. 9.The device of claim 4 further including spring means for returning saidcarrier member toward the other end of said reservoir.
 10. Apparatus forapplying liquid adhesive or the like to sheet or slab material, spacedapart support means, a coating roll and coating control roll rotatablysupported between said support means in rolling contact and defining areservoir therebetween, end plates at the opposite end of the rollsextending above the line of rolling contact of the rolls and arranged todefine the reservoir with the rolls, one of the end plates having anoverflow opening therein, a tank, a conduit extending from the overflowopening to the tank, a pump and conduit for delivering liquid from thetank to the reservoir; a member movable back and forth over saidreservoir and a generally flat surfaced paddlelike member connected tosaid member movable so that said paddlelike member forces liquid in thereservoir toward the overflow opening and means for rotating saidpaddlelike member as it nears said overflow opening and returning saidpaddlelike member toward the other end of the reservoir whereby aminimum surface area of said paddlelike member is presented to theliquid upon the return travel.